# Heat‐Treated Sucuk in Natural Casings: A Source of Higher Fermentative and Oxidative Volatile Compounds?

## TL;DR

This study compares how natural and collagen casings affect the quality and volatile compounds in Turkish sausages called sucuk, finding that natural casings increase oxidation products in heat-treated versions.

## Contribution

The study reveals that natural casings increase lipid oxidation products in heat-treated sucuk, offering practical guidance for casing selection in sausage production.

## Key findings

- Natural casings increased aldehydes, acids, and ketones in heat-treated sucuk compared to collagen casings.
- Volatile compounds helped differentiate production stages and casing types, especially in heat-treated sucuk.
- Natural casings led to higher browning and moisture in heat-treated sucuk but improved redness in traditional methods.

## Abstract

The effect of the type of casing on the quality parameters of Turkish‐style sausages (sucuk) is quite unexplored. So, this study aims to compare the effects of using natural or collagen casings in the production of naturally fermented (traditional) or heat‐treated sucuks on physicochemical properties (moisture, acidity, pH, and color values) and volatile compounds (VCs). The VCs, extracted by a solid‐phase‐micro‐extraction technique, were analyzed by gas chromatography‐mass spectrophotometry (SPME‐GC‐MS). Natural casing yielded a final product with the lowest pH, highest lightness, and redness in the traditional method, and the highest moisture and browning index in the heat‐treated method. Regardless of casing type, the traditional method produced sucuks with lower moisture, pH, a*, and browning index values. Cumin aldehyde, methyl eugenol, γ‐terpinene, pinene, and eugenol were the most abundant VCs identified in sucuk. The type of casing did not alter the volatile profile of naturally fermented sucuk. However, in heat‐treated sucuk, natural casing resulted in a higher accumulation of aldehydes, acids, and ketones in the final product compared to collagen casing. It is highlighted that natural casing may not be suitable for heat‐treated sucuk due to the abundance of lipid oxidation products. Principal component analysis showed that VCs were useful in differentiating between production stages and casing types, particularly for heat‐treated sucuk. This study demonstrates the impact of casing type on the quality of Turkish‐style sucuk and provides a theoretical basis for casing selection in future industrial production.

The aim of this study was to determine the optimal casing material (natural or collagen) for use in the production of fermented or heat‐treated sucuk. Natural casing improved the products' redness but increased browning and oxidative‐derived volatile compounds in heat‐treated sucuk. In the heat‐treatment method, collagen casing caused greater moisture loss in sucuks compared to natural casing. Volatile compounds derived from the oxidation of amino acids (3‐methyl‐2‐butenal) or fatty acids (heptanal, trans‐2‐heptenal, nonanal, trans,trans‐2,4‐heptadienal, trans,trans‐2,4‐decadienal, trans,cis‐2,4‐decadienal) emerged in natural‐cased sucuks produced by heat treatment. Furthermore, ethanol, acetic acid, and acetoin derived mainly from carbohydrate and pyruvate metabolism were found in high abundance in natural‐cased products, particularly in heat‐treated sucuk. These findings offer valuable insights for the food industry, helping producers select the best casing material to optimize product quality. This research provides practical guidance for improving sucuk production processes and may interest food scientists and industry professionals, and consumers.